package com.vic.framework.proxy;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import net.sf.cglib.proxy.MethodProxy;

/**
 * 代理链
 * @author VIC
 *
 */
public class ProxyChain {
	
	//目标类
	private final Class<?> targetClass;
	
	//目标对象
	private final Object targetObject;
	
	//目标方法
	private final Method targetMethod;
	
	//方法代理
	private final MethodProxy methodProxy;
	
	//方法参数
	private final Object[] methodParams;
	
	//代理索引
	private int proxyIndex = 0;
	
	//代理列表
	private List<Proxy> proxyList = new ArrayList<Proxy>();

	public ProxyChain(Class<?> targetClass, Object targetObject, Method targetMethod, MethodProxy methodProxy,
			Object[] methodParams, List<Proxy> proxyList) {
		super();
		this.targetClass = targetClass;
		this.targetObject = targetObject;
		this.targetMethod = targetMethod;
		this.methodProxy = methodProxy;
		this.methodParams = methodParams;
		this.proxyList = proxyList;
	}


	public Class<?> getTargetClass() {
		return targetClass;
	}


	public Method getTargetMethod() {
		return targetMethod;
	}

	public Object[] getMethodParams() {
		return methodParams;
	}
	
	/**
	 * <p>通过proxyIndex来充当代理对象的计数器，若尚未达到proxyList的上限，则从proxyList中取出相应的Proxy，并调用其doProxy方法
	 * 在Proxy接口的实现中会提供相应的横切逻辑，并调用doProxyChain方法，随后将再次调用当前ProxyChain对象的doProxy房
	 * 直到proxyIndex达到proxyList的上限为止，最后调用methodProxy的invokeSuper方法，执行目标对象的业务逻辑</p>  
	 */
	public Object doProxyChain() throws Throwable{
		Object methodResult;
		if(proxyIndex < proxyList.size()) {
			methodResult = proxyList.get(proxyIndex++).doProxy(this);
		}else {
			methodResult = methodProxy.invokeSuper(targetObject, methodParams);
		}
		return methodResult;
	}
	

	
	
}
